Prince of Thorns (The Broken Empire, #1) by Mark Lawrence; Audiobook review

This was an unexpectedly amazing book, #1 in an epic fantasy series. My audiobook was narrated by Joe Jameson who did a FANTASTIC job of the main character Prince Jorj.
Exceeded expectations, essentially because I had none. Someone recommended the author and this is what I found at the library.
#epicfantasybooks
Is this a 'grim-dark' ?I have heard so much about this classification, but I am still vague about the meaning of it.
Also on GoodReads / 6468180046